step(umc1,ci,tm(s,[ctxm(alpha_1_,umc,ip, (ip,umc1), (ip,umc1)),ctxm(alpha_1_,ci,ip, (ip,ci), (ip,ci))],pri(lst,[pri(h,[ctxm(alpha_1_,u,bsn,i_bsn,i_bsn)]),ctxm(alpha_1_,u,d_1, (i,d_1), (c,d_1)),ctxm(alpha_1_,u,d_2, (i,d_2), (c,d_2)),ctxm(alpha_1_,u,d_3, (i,d_3), (c,d_3))]))).